How Long do Cold Sores Last, with Abreva, Valtrex, Zovira & Scabs

If you are suffering from a cold sore and wondering how long it will stay on your lips, here is an insight on the duration it will take  without or with treatments such as abreva, valtrex and zoriva. Also, find out how long fever blister scabs will stay .

How long does a Cold Sore last to before Healing?

How long do fever blisters usually last in the mouth lips?

Cold sores develop in stages and this is what makes the period of time they last. Generally, from the first time you get a tingle, it is supposed to last about 8 to 10 days. This is the period of time it will take to completely heal.

This depends on other factors including the patency of your immune system, predisposing yourself to more complicating factors and medication or methods employed. The scab may however present for a longer while. More about the scab will be discussed in the later sections of this article.

If you happen to get an outbreak, the period might be longer and may even last a couple of weeks. One important thing to note is that once you have had a cold sore, the infection is not completely eradicated. Not even the antivirals do this. Hence, you will get cold sores once in a while. There are however ways you can take care of your lips to make them fewer.

how long does cold sore last
cold sore

The development of a cold sore(stages) is well calculated and this is what lays out the period. The lifespan is as follows:


You will start feeling a tingle a number of times in a day. Your lips will get a bit dry and tighter and redness follows. Swelling is imminent in the periphery of the tingle. This stage takes about 1 – 2 days.

Formation of blisters

This stage involves the formation of a lesion. The lesion follows your body’s immune system against the virus. At this stage, everyone who can identify a cold sore will mention it. The blister is fluid filled and contains colonies of viruses and they happen to be in millions.

It is at this stage that you are informed not to burst the blister or use other cosmetics. This is because of the increased risk of spread. This occurs in day 3 – 4.

Formation of ulcers

At this stage, the blisters burst naturally and form an indentation that is shallow known as an ulcer. The ulcer has a circular area of inflammation around it. Ulcers are painful and pain killers will be evidently used. It is important to keep your lips well hydrated since drying is eminent. This is seen in day 4 – 6

Formation of a scab

Approaching day 6, your cold sores start drying out and a crust is formed. This means that your ulcer is healing. Whether this stage will take longer depends on how you treat your lips. Delayed healing is seen when you leave your lips dry or take acidic food. Bleeding is not uncommon and itchiness is a sign of healing especially when it itches around the scab.


Healing continues into day 8 and 10 and at times this may extend to the 14th day. Expect that your scab will peel out and drop though leaving some minor reddish coloration on the lips. Have no worry as this will soon disappear.

What determines the duration cold sores will last?

Your cold sores may take a bit longer to heal. This is because there are determinants to the rate at which the cold sores heal. Here are some of them:

Co-application of other cosmetics

When you have already formed blisters, make sure that you avoid applying other facial cosmetics. When you are on an anti-viral topical drug or cream, make sure that you apply discriminately and gently to avoid any accidents.

When you do this, there is a chance that you will spread the infection to other parts of your lips. Furthermore, bursting them before due time will lead to formation of a scar and a re-infection will occur underneath.

Onset of treatment of the cold sores

The earlier you start the better. This is a known fad when it comes to treatment. Immediately you notice that there is a tingling sensation in your lips followed by redness, beware. Get the appropriate treatment by visiting a doctor or dermatologist.

When the cold sore is captured as early as it is still in the first of early second stage, then the period it will take to heal will be shorter. This is due to the reduced replication of the viral pathogen and hence fewer colonies to deal with. The later you start, the more the viruses and therefore, the longer the convalescence period.

Disregard to the stages of cold sore pathology

Now that you know that there are stages through which cold sores develop, disregarding this would increase healing time. Make sure that you do not burst the blister when it is not due. Let it do so naturally. There are stages in which drying may lead to further cracking and crusting.

This may form other lesions that could get re-infected. It is therefore important that you hydrate your lips. Most patients who have presented with cold sores at Mayo Clinic have had shorter periods of healing through regard to what to do in various stages.

Fever blister upper lip
Fever blister upper lip

Complementary management methods

There are methods that you can do by yourself to promote the healing process of cold sores. This includes, cool compress, maintenance of hygiene and home remedies. Cool compress and hygiene combined with antiviral agents such as Valtrex could greatly and significantly reduce the recovery period from cold sores.

How long do cold sores last with Abreva, Valtrex & Zovirax

How long does a cold sore last when using Abreva

Abreva is the only registered brand with docosanol, a behenyl alcohol. It has been used in cosmetics as an emulsifier and humectant. It is currently approved by the Foods and Drugs Administration (FDA) for the treatment of cold sores caused by the herpes simplex virus-1.

Its most important feature is its ability to inhibit the fusion of the host cell with the viruses’ envelope. This prevents entry into the host cells and hence its replication. Research further supports its use. Clinical efficacy has been studied by researchers including Sacks, SL et al and Katz DH et al in 2001 and 1991 respectively. These studies have yielded positive outcomes with the subjects involved.

With regard to the period of healing, Sacks et al were able to show that it shortens the healing time of cold sores by 17.5 hours on average. However, science can be challenged with more studies and two experiments have shown no statistically significant difference between Abreva and untreated infection sites; McKeough, M. B.; Spruance, S. L. (2001).

Abreva marketers Avanir Pharmaceuticals claimed that it was able to cut healing time in half. This claim was written on the product and raised qualms regarding its inability to deliver the claimed benefits. The company together with GlaxoSmithKline was sued in California forcing them to withdraw the claim form their products.

How long with Valtrex

Valtrex is a brand that markets the antiviral agent valacyclovir which is related to the prototype acyclovir.

Unlike the docosanol cream, Valtrex, this drug is formulated in caplets of 500 mg or 1000 mg valacyclovir. It has other excipients (inactive ingredients) including crospovidone and carnauba wax among others. Crospovidone and Povidone in the product could be more than just excipients owing to the fact that they are antimicrobials. Furthermore, titanium dioxide, also an excipient and regarded as inactive, could offer protective effect against sun burns.

how long cold sores last with valtrex
Valtrex tablets

Valtrex is taken on the earliest sign of a cold sore and this is known to reduce the healing time. It is taken as 2 grams 12 hours apart or twice daily for a day. The duration it takes to work also depends on other factors. As mentioned earlier, taking this drug early would reduce the time and the vice versa is true.

You may end up taking it  for a period of 7 to 10 days. Notice that this is the same times it takes for a cold sore to go through the development stages. There are cases in which it is prescribed for longer while the cold sores took a much shorter time to heal. Do not stop when you notice changes earlier than the end of the course.

However, when all factors are kept constant, it should start reducing the symptoms associated with cold sores within a period of 2 to 3 days. It therefore will take about 7 days to completely heal but the sooner you start, the shorter.

How long with Zovirax

This is a brand that markets the antiviral agent, acyclovir. It is a known treatment of herpes simplex virus and very effective with reduction of frequency of outbreaks and fewer symptoms. Zovirax is a cream applied to the cold sore. It promotes and reduces the period of healing. Just as Valtrex, it prevents the replication of the virus.

Zovirax is majorly indicated in those who are immunocompromised as these people get outbreaks of cold sores.

The duration of time it takes to elicit any benefit depends on how regularly you apply the cream though out the course of treatment. You should also cover the area applied with Zovirax to speed up entry into the skin.

Fortunately, Zovirax has a special penetrating formula, MAC-P, that allows speedy entry of the drug in to the skin shortening the recovery period. The period of recovery should be shorter when you use Zovirax five times a day at the same time each day. With such a level of compliance, the cold sores should be nearly healing by the 4th day.

Regardless of the time the cold sore heals, if Zovirax has been prescribed for you for longer period of time, it is wise to continue. Otherwise, there might be a reinfection. Remember that the medication does not completely eradicate the virus but just halts its multiplication. Hence, if stopped early, you will trigger another infection and the healing period will be longer.

How long does a sore throat last with a cold sore?

It should take about 5 to 7 days for a viral infection to limit. Sore throat is known as pharyngitis and is treated with antibiotics. You will start feeling better in the 2nd or 3rd day after starting the regimen. Again, you should make sure that you take the full regimen of antibiotics prescribed even if you have felt better so as to prevent recurrence and resistance.

Most pharyngitis infections are caused by viruses and these are self-limiting. How long it will take to heal from a sore throat and a cold sore will depend on other factors such as additional care you take. Even if they last longer than 7 days, it is rare.

If the sore throat has been caused by a strep bacteria, not taking the full course of antibiotics could trigger another infection known as rheumatic fever in which there is inflammation of the heart, joints and skin.

How long do cold sore scabs last

This is another worry that comes after suffering a cold sore through all its stages. Since you already understand the stages that lead to a scab, you will notice that the scab should last about 4 days. These are the last stages of the cold sore during which the scab peels and falls off.

It is worthwhile remembering that you need to keep your lips hydrated so that you prevent cracking of the scab and possible bleeding and reinfection thereafter.

One Comment

  1. The prescribing info for Valtrex is confusing. Treatment of early onset oral heroes (cold sore) is 2 gms at first sign or symptom of cold sore and 2 gms 12 hours after first dose.
    Seven to 10 days is incorrect.

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